This invention pertains to computer time measuring systems and more particularly is concerned with computer systems for timing races.
A particularly difficult race to time accurately is the so called whitewater slalom event. In this sporting event, a plurality of contestants in canoes or kayaks race serially down about a half mile stretch of rapids, attempting to maneuver through portals and around obstacles.
An important criteria to win is the time a contestant takes between the start and finish positions. Penalty times for missing a prescribed maneuver are added to the elapsed time. The contestant with the lowest overall time wins. Often the difference between contestant's times are fractions of a second. Further, the start and finish positions are so separated that a single official can not time the runs. Electronic time measuring apparatus is therefore used to enhance accuracy and to promptly report results. For this purpose a pivotable wand is located in the waterway at the starting position and closes a switch when activated by a racer's start. Photoelectric cells are used at the finish line. The wand and photoelectronic cell usually give precise time signals, but are not always reliable. The wand arrangement has been known to misfuction and not provide a start signal. Photoelectric cells can malfunction and generate a false signal.
Accordingly, it is desirable, and an object of the invention, to provide means to back up the electronic system while retaining the accuracy of the electronic system where possible.